Polyimide foam materiel and preparation method thereof

Abstract

The invention discloses a polyimide foam materiel and a preparation method thereof. The preparation method comprises the following steps: (1) mixing aromatic dianhydride with low molecular alcohol for an esterification reaction, so as to obtain a diacid diester solution; (2) mixing the diacid diester solution obtained in step (1) with a catalyst and furanidine for a reaction, so as to obtain a polyimide precursor solution; (3) drying the polyimide precursor solution obtained in step (2), carrying out foaming under vacuum and heating conditions to obtain a foaming intermediate, and conducting thermal imidization on the foaming intermediate to obtain the polyimide foam materiel. The polyimide foam materiel has the advantages that through adjustment of the temperature and the vacuum degree, the problem that in the prior art, the molecular mass of synthesized prepolymer powder is very low and causes foam combination in the conventional foaming process under the condition of very low material viscosity at foaming temperature can be effectively solved; meanwhile, the advantage that the precursor solution viscosity corresponding to the oligomer molecular mass is low can be kept, so that the polyimide foam materiel is easy to produce and process.

Description

technical field [0001] The invention relates to a polyimide foam material and a preparation method thereof, belonging to the field of polymer materials. Background technique [0002] Polyimide foam material is one of the research hotspots in recent years. The foam material has the characteristics of extreme temperature resistance (-250-450°C), radiation resistance, high flame retardancy, non-toxicity, oxidation resistance, hydrolysis resistance and the like. At the same time, the foamed polyimide material has low thermal conductivity and good sound absorption performance, and can be widely used in military and aerospace industries such as heat insulation for rockets, aircraft, aircraft carriers, submarines, etc., and civil flame retardant and heat insulation Fields such as insulation of high-temperature pipelines, etc. [0003] The research on polyimide foam material began in the 1960s. At that time, the Dupont company of the United States applied for the related patent US...

AI Technical Summary

Problems solved by technology

[0004] In all the above-mentioned patents, the common point is that high-purity raw materials are required when synthesizing the precursor solution, so as to ensure that the raw materials fed are in an equimolar ratio, and the reaction temperature is strictly controlled to obtain a high-molecular-weight polyamic acid or polyester amine salt precursor. Bulk solution, otherwise, problems such as foaming, bubble collapse, shrinkage, etc. will easily occur during foaming due to the inability to obtain a precursor solution with a sufficiently high bulk viscosity, and the preparation process is complicated

However, in actual industrial operations, harsh reaction conditions, high raw material costs, and high-viscosity precursor solutions limit the popularization of polyimide foam materials. In addition, the process of crushing dry polyimide precursors for foaming, If the uniformity of the powder particle size cannot be well controlled, it will not be possible to prepare a foam with uniform cells